US3869385A - Process for containing oil spills - Google Patents

Abstract

Oil spills on bodies of water are contained by applying a polyisocyanate and a polyamine thereto.

Description

11111140 tats 'atet 1 1 Stanley et a1.

[ 1 PR CESS 012 CONTAINING OIL SPILLS [75] Inventors: William 1.. Stanley, Richmond;

Allen G. Pittman, El Cerrito, both of Calif.

[22] Filed: Oct. 18, 1971 [21] Appl. No.: 190,320

[52 11.5. (31.; 210/53, 210/54, 210 1210. 21 [51 Int. Cl C02b 9/02 [58 Field 01 Search 210/40, 42, 59, DIG. 21, 210/43, 47, 52, 53

[56 References Cited UNITED STATES PATENTS 3,415,745 12/1968 lsaacson et a1. 210/54 3,462,295 8/1969 Elmquist et a1. .1 117/143 R 2/1970- Roth 210/40 X 1 1 Mar. 4, 1975 3,536,616 10/1970 Kordoh et a1 210/40 3,591,524 7/1971 Eriksen 210/40 X 3,657,125 4/1972 Strick'man 210/40 3,755,189 8/1973 Gilchrist 210/42 X 3,810,835 5/1974 Perm. 210/59 FORElGN ATENTS 0R APPLICATIONS 979,978 1/1965 Great Britain 210/1310. 21

OTHER PUBLICATIONS Firms Seek Ways to Control; Disperse Oil Slicks,

Chemical & Engineering News, July, 1,1968, pp.

Primary E.\-aminer-Thonias G. WySe Takacs 57 ABSTRACT Oil Spills on bodies of water are contained by applying PROCESS FOR CONTAINING OIL SPILLS A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

DESCRIPTION OF .THE INVENTION The invention relates to and has among its objects the provision of novel processes for containing oil spills on bodies of water. Further objects of the invention will be evidentfrom the following description wherein parts and percentages are tied.

Oil spilled from tankers transporting the same .or leaked-from offshore wells is becoming an increasing threat to the environment. It was reported recently that the mid-Atlantic Ocean has become fouled with asphalt-Iike lumps and other gunk presumably from oil. Spills and leaks are creating havoc with-the wildlife that inhabit oceans, bays, and the surrounding areas. Numerous birds have died because their bodies have been drenched with thick crude oil. Fish, seals, and the like have also felt the effects of mans upset of their environment. Asthe demand for petroleum products rises, the chances of a spill or leak are considerably enhanced.

The present invention provides a means for obviating the problems outlined above. More particularly, the invention enables oil spills to be contained, that is, kept within a limited area so that the oil can be collected ef ficiently and economically. On the other hand, where.

the spill is not'contained, the oil'is dispersed'by wind or wave action over a wide area, with the result that its collection is rendered difficult and even impossible in extreme cases. The process of the invention is applicable-for the containment of oil spills on bodies of water by weight unless otherwise speciof all kinds, including those containing fresh, brackish,

or salt (sea) water, and the oil may be any liquid petroleum material, including crude oil,,residual fuel oils, and distilled products such as fuel oils, kerosene, diesel oils, etc. The expression oil spill"'is employed herein to designate a pool or mass of oil floating on a body of water, and without distinction as to the source of the oil or the manner by which it was released.

Basically, the process of the invention involves applying a polyisocyanate and a polyamine to the oil spill. The said reagents react, yielding a polymer'which entraps the oil, forming a rubbery gelled mass, and thereby preventing dispersion of the oil. The reagents may be applied to the entire area of the oil spill or, more preferably, to selected parts thereof-for example,.to the outer periphery thereof.

In a typical practice ofthe invention, the reagents are applied'to the outer periphery of the body of oil which constitutes the spill. The applicationcan be accomplished by means of a boat or other vessel which circles the oil spill and concomitantly deposits the reagents on the edge of the oil. Alternatively, the reagents can be applied to the perimeter of the oil spill by low-flying aircraft. To facilitate their application, the reagents may be employed in the form of solutions in kerosene or other inert solvent. Soon after the reagents are applied, a rubber-like gel is formed and this barrier or.

In cases where there is severe wind or wave action,

the formation of a peripheral dam may not be sufficient to contain the spill. In such case, the reagents may be additionally applied over interior surface portions of the spill. The resulting'increase in viscosity of the entire body of oil will then tend to resist the wave/wind action and hold the body together as a coherent entity.

In situations where the oil is emerging from some source which can be reached-such as a break in the sides of a tanker-the reagents can be applied to the liquid as it leaves the source. The resulting increase in viscosity due to formation of the polymer will cause the resultingspill to take the form of a coherent coagulated mass which can be c'ollected readily by conventional equipment such as skimmers or the like.

In apractice of the invention, the polyisocyanate and polyamine reagents may be applied simultaneously. Alternatively, they may be applied successively. In the latter case it is preferred that the polyisocyanate be applied first. With any mode of application, the two reagents are preferably used in such. proportion as to furnish free isocyanate groups in approximately equimolar proportion to amino groups. This proportion, however, need not be vigorously applied as the polymer will be formed properly with an excess ofeither of the reactive moieties. It is obvious, nonetheless, that where equimo- I lar proportions offree isocyanate and amino groups are used, the reagents will be most efficiently utilized.

In'cases where the spill is contained by forming a polymer dam about its perimeter, the oil within the soformed dam can be removed by conventional mechaniv .cal means and re-used directly or after treatment to separate any occluded water. In cases where the polyisocyanate and polyamine are appliedto considerable surface areas of the spill or actually mixed with an outflow of oil, the recovered mass of oil will require more extensive purification. For example, distillationcan be employed to segregate the volatile oil fraction from the essentially non-volatile polymeric material.

' An advantage of the invention is that it does not dematerials. Generally, these materials must be used in large excess because the amount of oil-absorbed by these is relatively small. The process of the invention is notbased on absorbancebut on "the principle of containingthe oil by a thickening or coagulating effect, with the result that relatively small proportions of the reagents are effective. For example, in many. cases the use of about I to 3 partsofpolyisocyanate plus polyamine per 100 parts of oil is sufficient to attain the dedam prevents dispersion of the oil. Conventional means such as pumps or skimmers can then be used to harvest sired containment effect.

I The Reagents (General) 2. They should be at lcast partially miscible with oil and essentially immiscible with water;

With regard to Item I, it is important that the rea- I gents float on the water rather than sink or cause the oil to sink. The requirement is'easy. to fulfill as most organic compoundsunless they contain heavy atoms such less than that of the as bromine, iodine, etc. have a density less than that of fresh or salt water.

The second criterion is also easily fulfilled. One can readily select those compounds which contain enough carbon chains, rings, or other oleophilic constituents to provide the desired oil-miscibility combined with watcr-immiscibility. In any particular case, the'suitability of a candidate compound can be determined by simple solubility tests or by reference to the usual chemical handbooks.

An additional itemis that best results are obtained when both thepolyisocyanate and polyamine do not exert a dispersing effect on oil films. In the case of the polyisocyanates this condition is readily met because these compounds in general do not exert any oil dispersion effect. In the case of the polyamines a greater degree of selection is required because many polyamines-particularly those which'contain primary amine groups-will disperse oil films. A candidate compound can be tested for this property as follows:

A small pan is partly filled with 5% salt water. Then, crude oil is placed on top of the-water where it remains as a coherent film. A few drops of the candidate compound are .placed on the oil film and the system observed. If the addition of the compound causes the film to be dispersed, that is, to move away from the locus of the applieddroplet, this compound is not a preferred one. If, on the other hand, the oil film remains in place as a coherent film, the compound is one which does not cause oil dispersion and is a preferred reagent for use in accordance with the invention.

' Ingeneral, wehave observed that the desired property (no dispersion effect on oil films) is displayed by those polyamines wherein the hydrophilic properties imparted by the amine groups are balanced by alkyl groups which contain 4 or more carbon atoms or by other organic groups which impart oleophilic properties. Typical preferred polyamines are those wherein each amine group is secondary, for example, contain-- ing an N-alkyl substituent having at least 4 carbon atoms. a

The Polyisocyanates of toluene-2,4-and 2,6-

vention are the compounds produced by. the polymerization of fatacids, followed by conversion to diisocyanates. Such compounds are disclosed in US. Pat. No. 3,462,295, and may be represented by the formula R cn nco 1,

wherein is an integer selectedfrom 0 to l,.\' is an integer of 2 to about 4, and R is the hydrocarbon group of polymeric fat acids R(COOH),, said polymeric fat acids having been prepared by polymerizing fat acids of 824 carbon atoms.

Coming into special consideration is the compound of the aforesaid class which is commerciallyavailable from General Mills, Inc. under thenam'e of DDl diisocyanate, and which is derived from dimer acid pro duced by the polymerization of C fat acids. The compound has the structure taining 18 carbon atoms. Some of the properties ofDDl diisocyanate are: a low viscosity liquid, specific gravity 0.924, NCO content 14%, soluble in benzene, hexane, and other common organic solvents. The compound is reported ,to have lower animal toxicity than various other diisocyanates such as hexamethylene diisocyanate and 2,4-toluene diisocyanate.

Also useful in a practice of the invention are polyurethanes which contain free isocyanate groups. These compounds may be prepared, as well kno'wn'in the art, by reacting a polyol with a polyisoc'yanate,'using an excess of the latter to ensure provision offree isocyanate groups in the product. A typical, but by no means limiting, example is illustrated below:

H0 Z- Z- Z 'C Z-Q H .Polyether polyol Polyisocyanate (In the above formulas, m represents the number of tetramethyleneether repeating units. This may range, for

example, about from to 50.)

ethylene glycol glycerol pentaerythritol dipentaerythritol propylene glycol trimethylene glycol 1,2-butylene glycol 1,3-butanediol l,4-butanediol l,5-pentanediol l,2hexylene glycol 1-,10-decanediol 1,2-cycloheXanediol 2-butene-l, diol 3-cyclohexene-l,l-dimethanol 4-methyl-3-cyclohexenel ,l-dimethanol 3methylene-l ,S-pentanediol diethylene glycol (2-hydroxyethoxy)-l-propanol 4-(2-hydroxyethoxy)-l-butanol S-(Z-hydroxypropoxyJ-l-pentanol l-(Z-hydroxymethoxy)'-2-hexanol l-(Z-hydroxypropoxy)-2-oxtanol 3-allyloxyl ,S-pentanediol 2-allyloxymethyl-Z-methyl-l ,3-propanediol [(4-pentyloxy)methyl]-'l ,3-propanediol 3-(o-propenylphenoxy)-l,2-propanediol thiodiglycol 2,2-[thiobis(ethyleneoxy)ldiethanol I polyethyleneether glycol (molecular weight about 2,2'--isopropylidenebis(p-phenyleneoxy)diethanol 1,2,6-hexanetriol 7 1,1 ,l-trimethylolpropane 3-( 2-hydroxyethoxy)-l ,2'-propanediol 3-( 2-hydroxypropoxy )-l ,2-propanediol 2,4-dimethyl-2-(Z-hydroxyethoxy)methylpentanedh ol-l,5

1,1,l-tris [(2-hydroxyetl1oxy)methyl]ethane l,l,l-tris[(Z-hydroxypropoxy)methyl]propane triethanolaminetriisopropanolamine resorcinol pyrogallol phloroglucinol Roommate-terminated polyether polyurethane hydroquinone 4,6-di-teriarybutyl catecho catechol orcinol methylphoroglucinol hexylresorcinol 3-hydroxy-2-naphthol 2-hydroxyl -naphthol 2,5-dihydroxy-l-naphthol bis-phenols such as 2,2-bis-(p-hydro xyphenyl) propane and bis-(p-hydroxyphenyl)-methane l,l2-tris-(hydroxyphenyl)-ethane 1 l,l,3-tris-(hydroxyphenyl)-propane Hereinabove it has been noted that the polyurethanes may be derived from polyether polyols. Among the polyether polyols which may be so used are those prepared by reaction of an alkylene oxide with an initiator containing active hydrogen groups, a typical example,

of the initiator being a polyhydric'alcohol such as ethylene glycol. The reaction is usually carried out'in the presence of either an acidic or-basic catalyst. Examples ofalkylene oxides which may be employed in the syn thesis include ethylene oxide, propylene oxide, any of the isomeric butylene oxides, and mixtures of two or more different alkylene oxides such as mixtures of ethylene and propylene oxides. The resulting polymers contain a.polyether backbone and are terminated by hydroxyl groups. The number of hydroxyl groups per polymer molecule is determined by the functionality of the active hydrogen initiator. For example, a difunctional alcohol such as ethylene glycol'(as the active hydrogen initiator) leads to polyether chains in which there are two hydroxyl groups per polymer molecule. When polymerization of the oxide is carried'out in the presence ofglycerol, a trifunctional alcohol, the resulting polyether molecules contain an average of three hydroxyl groups per molecule. Even higher funcv tionality-more hydroxyl groups-is obtained when the oxide is polymerized in the presence of such polyols as pentaerythritol, dipentaerythritol, and the like. In similar manner, any of the above-listed polyhydric alcohols and phenols "may be reacted with alkylene oxides toproduce useful polyether polyols. p

The polyester-polyols which may be employed as precursors for the polyurethanes are mostreadily prepared by condensation polymerization of a polybasic acid with a polyhydric alcohol or phenols. These reactantsare used in such proportion that essentially all the acid groupsare esterified and the resulting chain of ester units is terminated by hydroxyl groups. Representative examples of polybasic acids are oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, ,pimelic acid,.suberic acid, azelaic acid, sebacic acid, bra ssylic acid, thapsic acid, maleic acid, fumaric acid, glutaconic acid, oz-hydromuconic acid, ,B-hydromuconic acid, a-butyl-a-ethylglutaric acid, a,B--diethylsuccinic acid, o-phthalic acid, isophthalic acid, terephthalic acid,

, 7 hemimellitic acid, trimelliticacid, trimesic acid, mellophanic acid, prehnitic acid, pyromellitic acid, citric acid, benzenepentacarboxylic acid, 1,4- cyclohexanedicarboxylic acid, diglycollic acid, thiodiglycollic acid, dimerized oleic acid, dimerized linoleic acid, and the like. Representative examples of polyhydroxy compounds for reaction with the polybasic acids includes ethylene glycol, 1,3-propylene glycol, 1,2-

, propylene glycol, l',4-butylene glycol, 1,3-butylene glycol, 1,2-buty'lene glycol, butene-l,4-diol, l,5-pentane diol, l,4pentane diol, 1,3-pentane diol, 1,6-hexane diol, hexene-l,6-diol, 1,7-heptane diol, diethylene glycol, glycerine, trimethylol propane, 1,3,6-hexanetriol, triethanolamine, pentaerythritol, and any of the other polyhydric alcohols or phenols listed hereinabove in connection with the preparation of polyether polyols. Estersof the hydroxyl-containing acid, ricinoleic acid, form another category of useful polyester polyols.

Typically, one can use esters of ricinoleic acid with eth-' ylene glycol, propylene glycol, glycerol, pentacrythritol, diglycerol, dipentaerythritol, polyalkyleneether glycols, and the like. Representative of this category of polyester polyols is castor oil which is composed mainly ofthe tri-glyceride of ricinoleic acid.

'. The Polyamines With regard to the polyamine reagent required for a practice of the invention, one can use any of the aro- 'matic, aliphati'c,'or heterocyclic compounds which merization offatacids', followed by conversion to polyamines. Such compounds are disclosed in US. Pat. No..

3,462,295, and may be represented by' the formula R [wring-W211 wherein y is an integer selected fromO and l, x is an integer of 2 to about 4, and R is the hydrocarbon group of polymeric fat acids R(COOH),, said polymeric fat acids having been prepared by polymerizing fat acids of 8-24 carbon atoms. I

We have found that certain polyamines are free from oil-dispersing characteristics and thus particularly useful in the process of the invention. These polyamines are copolymers prepared by copolymerizing the follow ing monomers:

A. an alkyl ester of the structure Allcms-G- G a fca wherein Alk represents an alkyl group containing 8 to carbon atoms and X represents H or CH and B. An aminoalkyl ester of the structure n mi-ca -ca -o-c-c 011 wherein R represents an alkyl group containing 1 to 20 carbon atoms and X represents H or CH In a typical example, lauryl methacrylate (about 1 to 5 moles) is copolymerized with t-butylaminoethyl methacrylate (lmole) by applying conventional polymerization techniques-heating to about 80-l00 C. in the presence of an initiator such as a,a'-azobisisobutyronitrile.

EXAMPLES The invention is further demonstrated by the follow-- ing illustrative'examples.

The polyisocyanate used in Examples-2 and 3 was DDldiisocyanate, a product derived from dimer acid produced by dimerization of C fat acids, and described hereinabove.

The polyamine used inExamples 2 and'3'was prepared as described in Example 1.

EXAMPLE 1 Lauryl methacrylate (10' parts) was mixed with t-butyl-2-aminoethyl methacrylate 01,0: -azobisisobutyronitrile (0.] part). The mixture was heated at about C on a steam bath for 2 hours, The solid copolymer so formed was dissolved in an equal amount of kerosene and the resulting solution em ployed in the following examples.

EXAMPLE 2 A small enamel pan approximately 7 inches X 12 inches); was filled to adepth of about 2 inches with 5% brine. Approximately 10 gfof Alaska crude oil was poured on the surface of the water. The outer edge of the resulting oil slic'k was treated with about 0.3 g. of DDI'(applied dropwise), followed immediately by 0.6 g. of the kerosene solution of the polyamine (also applied dropwise). The polymer gel formed rapidly, thus containing the oil within arubber-like ring.

EXAMPLE 3 An oil spill was prepared as described in Example 1. About 0.3 g. of DDI was added to the center of the. oil. After approximately 1 minute, 0.6 g.'of the polyamine solution was added in the same place. In'a matter of" minutes the entire oil spill was converted to a gel-likev coherent mass which was easily removed from the surface of the water.

Having thus described our invention, we claim: l. A process for containing an oil spill on a body of water, which comprises applying to the oil spill a polyisocyanate and a polyamine, in such amounts as to furnish free isocyanate groups in approximately equimolar proportion to amino groups, and wherein both the polyisocyanate and the polyamine have a density less than that of the water in said body and are at least partially miscible with oil but essentially immiscible with water. 2. The process of claim 1 wherein polyisocyanate and polyamine are applied simultaneously. 1

3. The process of claim 1 wherein the polyisocyanate I and polyamine are applied successively.

2 parts) I and 4. The process of claim 1 wherein the polyisocyanate and polyamine are applied to the the oil spill.

5. The process of claim 1 wherein both the polyisocyanate and the polyamine do not exhibit a dispersion effect on oil films. v

6. The process of claim 1 wherein the polyisocyanate has the structure I wherein y is an integer selected from to l, x is an integer of 2 to about 4, and R is thehydrocarbon group of polymeric fat acids R(COOH),, said polymeric fat acids having been prepared by polymerizing fat acids of 8-24 carbon atoms 7. The process of claim 1 wherein the polyamine is a copolymer of a. an alkyl ester of the structure alts-W0 0 m 0H wherein alk represents an alkyl group containing 8 to peripheral portion of I 10 20 carbon atoms and X represents H or CH and b. an aminoalkyl ester of the structure wherein R represents an alkyl group containing 1 to 20 carbon atoms, and X represents H or CH;,.

8. A process for limiting the dispersion of an oil spill on a body of water, which comprises entrapping selected portions of the oil in a polymer tially miscible in oil but immiscible in water, and donot exhibit a dispersion effect on oil films.

Claims (8)

1. A PROCESS FOR CONTAINING AN OIL SPILL ON A BODY OF WATER, WHICH COMPRISES APPLYING TO THE OIL SPILL A POLYISOCYANATE AND A POLYAMINE, IN SUCH AMOUNTS AS TO FURNISH FREE ISOCYANATE GROUPS IN APPROXIMATELY EQUIMOLAR PROPORTION TO AMINO GROUPS, AND WHEREIN BOTH THE POLYISOCYANATE AND THE POLYAMINE HAVE A DENSITY LESS THAN THAT OF THE WATER IN SAID BODY AND ARE AT LEAST PARTIALLY MISCIBLE WITH OIL BUT ESSENTIALLY IMMISCIBLE WITH WATER.

2. The process of claim 1 wherein polyisocyanate and polyamine are applied simultaneously.

3. The process of claim 1 wherein the polyisocyanate and polyamine are applied successively.

4. The process of claim 1 wherein the polyisocyanate and polyamine are applied to the peripheral portion of the oil spill.

5. The process of claim 1 wherein both the polyisocyanate and the polyamine do not exhibit a dispersion effect on oil films.

6. The process of claim 1 wherein the polyisocyanate has the structure R-(CH2)y-NCO)x wherein y is an integer selected from 0 to 1, x is an integer of 2 to about 4, and R is the hydrocarbon group of polymeric fat acids R(COOH)x, said polymeric fat acids having been prepared by polymerizing fat acids of 8-24 carbon atoms.

7. The process of claim 1 wherein the polyamine is a copolymer of a. an alkyl ester of the structure

8. A process for limiting the dispersion of an oil spill on a body of water, which comprises entrapping selected portions of the oil in a polymer matrix, the polymer being formed in situ by reaction of a polyisocyanate and a polyamine, applied to the oil in such amounts as to furnish free isocyanate groups in approximately equimolar proportion to amino groups, and wherein both of said reactants have a density less than that of the water in said body, are at least partially miscible in oil but immiscible in water, and do not exhibit a dispersion effect on oil films.